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Short stands for Forte?


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I'm about to own a pair of Forte lls for HT use and I'll need to raise them 3-5". They have the stock risers. Anyone have any recommendations? Am also wondering how well foam monitor isolation wedges might work as an option. The Foam Factory has a selection that (as described) would accomodate the size and weight of the Forte but have a 4 degree tilt. Thanks in advance for your thoughts and suggestions.

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I made some stands that raised my F2's 10" off the floor as test to try to reduce some

"boom in the room". I believe it worked but need more time to evaluate. My wife and I do most

of our listening while upright and raising the mids can't be a bad thing.

 

 

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Beware legs, unless you take steps to avoid a cavity under each speaker.  The little trim indent under the stock Forte II won't hurt, and may be part of the design.  Paul W. Klipsch warned against legs that form cavities in his cardinal rules:

 

5. Freedom from cavities. The space under a speaker box formed by mounting it on legs can destroy the bottom octave of response and deteriorate the next 2 octaves.

 

Some people on the forum have put rigid, solid wood "aprons" around the DIY riser, flush with the front, sides, and backs of their speaker, to avoid a cavity.  An alternative is to put a solid block of wood under the Forte II, the same length and width as the bottom of the Forte cabinet, your desired 3" to 5" thick, and firmly attached to avoid rattles.

 

Here are PWK's rules.  We don't see them often enough, and there are abridged versions of them floating around.  I think this list is complete.

 

Eight Cardinal Points of Reproduction 

 

 

1.Freedom from distortion. Minimum distortion requires small amplitudes of air mass movements, even at peak transient power output. Bass diaphragm motion should not exceed 1/16 inch. Corner placement reduces distortion three fourths.

 

2.Optimum size of speaker. Large enough to reproduce the lowest audible bass tone at peak transient power output without distortion; not so large as to produce a separation of bass and treble events. Corner placement increases effective size of speaker 4 times.

 

3.Freedom from rattles.

 

4.Freedom from shadows. Obstructions between high frequency speaker and listeners can not be tolerated - treble wave-lengths do not turn corners. 

 

 5.Freedom from cavities. The space under a speaker box formed by mounting it on legs can destroy the bottom octave of response and deteriorate the next 2 octaves.

 

6.Adequate spacing for stereo. In a 14 x 17 foot room, for example, the 17-foot wall is apt to be best for the stereo speaker array.

 

7.Accurate spatial values. Ability to localize the virtual sound sources in their original spatial relationships requires 3 widely spaced speakers, regardless of size or type, retention of this quality over a wide listening area requires toe-in of the flanking speakers.

 

8.Flanking speakers toed-in. Such toe-in is naturally provided by corner speakers. The effect is to reduce shift of the virtual sound source for different listener locations. This is the only way to achieve a wide area for listening.

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6 hours ago, garyrc said:

Beware legs, unless you take steps to avoid a cavity under each speaker.  The little trim indent under the stock Forte II won't hurt, and may be part of the design.  Paul W. Klipsch warned against legs that form cavities in his cardinal rules:

 

5. Freedom from cavities. The space under a speaker box formed by mounting it on legs can destroy the bottom octave of response and deteriorate the next 2 octaves.

 

Some people on the forum have put rigid, solid wood "aprons" around the DIY riser, flush with the front, sides, and backs of their speaker, to avoid a cavity.  An alternative is to put a solid block of wood under the Forte II, the same length and width as the bottom of the Forte cabinet, your desired 3" to 5" thick, and firmly attached to avoid rattles.

 

Here are PWK's rules.  We don't see them often enough, and there are abridged versions of them floating around.  I think this list is complete.

 

Eight Cardinal Points of Reproduction 

 

 

1.Freedom from distortion. Minimum distortion requires small amplitudes of air mass movements, even at peak transient power output. Bass diaphragm motion should not exceed 1/16 inch. Corner placement reduces distortion three fourths.

 

2.Optimum size of speaker. Large enough to reproduce the lowest audible bass tone at peak transient power output without distortion; not so large as to produce a separation of bass and treble events. Corner placement increases effective size of speaker 4 times.

 

3.Freedom from rattles.

 

4.Freedom from shadows. Obstructions between high frequency speaker and listeners can not be tolerated - treble wave-lengths do not turn corners. 

 

 5.Freedom from cavities. The space under a speaker box formed by mounting it on legs can destroy the bottom octave of response and deteriorate the next 2 octaves.

 

6.Adequate spacing for stereo. In a 14 x 17 foot room, for example, the 17-foot wall is apt to be best for the stereo speaker array.

 

7.Accurate spatial values. Ability to localize the virtual sound sources in their original spatial relationships requires 3 widely spaced speakers, regardless of size or type, retention of this quality over a wide listening area requires toe-in of the flanking speakers.

 

8.Flanking speakers toed-in. Such toe-in is naturally provided by corner speakers. The effect is to reduce shift of the virtual sound source for different listener locations. This is the only way to achieve a wide area for listening.

Agreed. M experimentation with my Quartets confirm this. A solid, 4 sided stand enforces the bass responce. When lifted with a cavity, it was reduced. However, with a 'bearded' stand, where the front of the stand is flush with the speaker and extends to the floor, increases bass output by 6db or so.

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garyrc, thanks for the info on legs and cavities.

 

A bit of a derail…

 

What are the physics of the impact to bass from cavities?  Does this cause a reduction of the boundary effect, and would elimination of the cavity restore the some of the boundary effect?

 

Taken to the extreme, would the typical bookshelf speaker on stands have the cavity effect because stands are rarely the full length and width dimensions of the speakers.

 

I built risers to get the mids and highs close to ear level when standing in the unfinished part of my basement (see pic).  Should I consider enclosing the risers to improve bass response?  The room is a large, open space, so not sure how much this would matter.

forte.jpg

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See avatar for the stands...regarding Cardinal Rule 5, with furniture legs or open stands like I use, there indeed is a loss of boundary reinforcement in the lower octaves, but that can be countered by using subs, applying eq, or both.  Also, elevating and aiming the mids appropriately can improve imaging a great deal.

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  • 1 month later...

Just returning to this. Raising it to get the mid horns at ear level. I'll actually need to raise it about 8". Good to know about the issues with a cavity underneath. I've been using a pair of solid blocks and the height really helps with imaging. I'm now on a quest to find something that doesnt look like it belongs in a dorm room. Thanks for the replies. 

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  • 2 years later...
51 minutes ago, Stephen Parker said:

Hi, Has anyone considered filling the stock Forte II stands/risers with sand and then sealing them? I am considering this but will it alter the performance of the speakers?

here is a nice four post stand for a Forte lll stock risers removed columns are fallible. You want to raise any speaker so that the centre of the mid driver is centred upon your seated ear level this will result in the best response stage and image. These are custom Skylan Stands.

Klipsch Forte 3 on Skylan Stands.JPG

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2 hours ago, Stephen Parker said:

Hi, Has anyone considered filling the stock Forte II stands/risers with sand and then sealing them? I am considering this but will it alter the performance of the speakers?

 

I'd guess any performance alteration derived from that would border very hard on the limits of perception and/or measurement, if it accomplished anything at all beyond maybe lowing the center of mass 1/4".

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  • 1 year later...
On 3/12/2020 at 6:07 AM, pzannucci said:

Getting ready to do the same thing with a set of Forte IIs I have.  Trying to decide the height and possible angle.

I have settled on removing the original base and raising the bottom of the speakers (Forte II) 10 inches off the floor. Literally remedies so many issues that the Klipsch engineers engineered into the speakers. 

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